I have been invited to "A Night of Elegance" dinner party.

Expensive tickets, nice French dinner, wine, etc. We actually found a sitter! It's February in Wisconsin. Expected temp that evening: 10 degrees, tops. Definitely lots of ice on the ground, possibly snow. An older, more conservative crowd, most probably won't dress beyond business casual.

I am a 34 year old SAHM. I am borderline petite (5'4 1/2"), borderline plus size. I hover around a 16, sometimes I fit in the misses, sometimes I don't. I would like to dress up and look feminine, but avoid being silly. However, I don't want to look too old and frumpy, either. I have dark brown, almost black hair, and at this time of year, a very pale white complexion. I look good in jewel tones, I look horrible in light wash browns and greens and the trendy earthy colors.
I hate the loud prints that are popular--especially in the plus sizes. I think they are clown-like.

I have some basic dress pants in black, charcoal grey and brown that may help round out an outfit? Like with a killer top? I have basic black and brown leather booties, but I was thinking of trying to find dressier shoes? I have plenty of jewelry to dress up an outfit, and I can do nice hair and makeup. It just occurred to me that I do not currently have a little black dress. (I can feel all the New Yorkers coiling in shock)

Budget: up to $300. I have access to Kohl's, Macy's, Coldwater Creek, Ann Taylor, Younkers, H&M, Banana Republic, Talbots, David's Bridal, etc.

Would a black blazer and a jewel toned top look too business and boring? A-line dress? Where would I find one and what to cover up arms with?

photo:http://i567.photobucket.com/al.....0030-2.jpg

HELP PLEASE!!! THANK YOU!!!